Ejector performance

Ejector Performance The performance of any ejec tor is a function of the area of the motive-gas nozzle and venturi throat, pressure of the motive gas, suction and discharge pressures, and ratios of specific heats, molecular weights, and temperatures. Figure 10-102, based on the assumption of constant-area mixing, is useful in evaluating single-stage-ejector performance for compression ratios up to 10 and area ratios up to 100 (see Fig. 10-103 for notation). 

Aftercondensers operate at atmospheric pressure. They do not affect the steam economy or ejector performance, but they do avoid the nuisance of exhausting steam to the atmosphere, thus, they allow steam to be recovered. They also serve as silencers on the ejectors, and with barometric types they can absorb odors and corrosive apors. 

Figure 6-11 A. Comparison guide for steam ejector performance. As absolute pressure is reduced, the number of stages increases for a given capacity. The same steam consumption is used for each design. By permission, Berkiey, F. D. [1].

Blatchley, C. G., Controlling Ejector Performance, 1956, Schutte and Koerting Co. 

CFD simulations of Kandakure et al. (2005) also showed that for > 4 there is very little change in the major ejector performance parameters. 

Effect of Operational Changes on Critical Flow Ejector Performance... 

The system concept, design options for thermal integration and high compactness and experimental results for the component development will be discussed. Ejector performance... 

The influence of temperature on the ejector performance was tested in a furnace. Figure 10 shows the results for nozzle inlet temperatures between 23 °C and 693 °C. 

Improve ejector performance. Providing a source of colder cooling water for. the interstage condensers is one method of achieving this objective. Lower top pressure will translate into lower flash-zone pressure. 

Throttling either the inlet or discharge from an ejector, or throttling the motive fluid, is not generally successful because of the impact they have on ejector performance. However it is common for the ejector spillback to be closed and the pressure controller on manual. This is not a reflection on the performance of the scheme. It can be economically very attractive to operate the column at the lowest possible pressure, even if this means the pressure fluctuating somewhat. We will cover later in the chapter techniques for compensating for such fluctuations so that product composition is not affected. And we will also return later to pressure optimisation. 

Martin, G.R. (1997) Understand real-world problems of vacuum ejector performance. Hydrocarbon Processing, 76 (11), 63-75. Power, R.B. (1993) Steam Jet Ejectors for the Process Industries, McGraw-Hill. Produktkatalog (2009), GEA Wiegand GmbH, Ettlingen. 

Adequate factors of Eq. 5.43 ( Ti K2K2) are depend on ejector geometry and define ejector performances. 

Marsano et al. [18] investigated the influence of ejector performance on a solid oxide fuel cell recirculation (recycle) system. This investigation concerned a 240 kW power system. They found that the ejector plays a key role during ofif-design operation. 

Marsano F, Magistri L, Massardo AF (2004) Ejector performance influence on a solid oxide fuel cell anodic recirculation system. J Power Sources 129(2) 216-228 Ferrari ML, Traverso A, Magistri L, Massardo AF (2005) Influence of the anodic recirculation transient behaviour on the SOFC hybrid system performance. J Power Sources 149 22-32... 

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